Text and Data Mining valid from 2019-04-23
Received: 2 July 2018
Accepted: 8 April 2019
First Online: 23 April 2019
Ethics approval and consent to participate
: The current study is a secondary analysis of the de-identified China Health and Retirement Longitudinal Study (CHARLS) public data. The original CHARLS was approved by the Ethical Review Committee of Peking University, and all participants signed the informed consent at the time of participation.
: Not applicable.
: The authors declare that they have no competing interests.
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